Painting device for building

The utility model discloses a painting device for a building. The painting device comprises a lifting structure, an adjusting structure and a bottom plate. The lifting structure comprises a supporting column and a connecting plate, a tooth groove is formed in the inner side of the supporting column, a sliding groove is formed in the front side face of the supporting column, a sliding block is fixedly connected to the rear end of the connecting plate, and the sliding block is in sliding connection with the sliding groove; a protective shell is fixedly connected to the rear end of the connecting plate, a first motor is fixedly connected to the rear side of the protective shell, a gear is arranged in the protective shell, the gear is connected to the surface of the output end of the first motor in a sleeving mode, and the gear is connected with the tooth groove in a meshed mode. A first motor works to drive a painting roller to move up and down, meanwhile, when a hydraulic rod works, the painting roller can rota